Nokia World's first ice touchscreen virtually burns

IT BRINGS a whole new meaning to freeze frame. A team at Nokia in Finland has created one of the unlikeliest computer displays yet - the world's first ice touchscreen.

It is not a practical device, of course, but the screen is being seen as a step towards an era in which the surfaces around us gain computing capabilities (see "What is ubiqitous computing?").Nokia World's first ice touchscreen virtually burns

"This was a playful experiment, but one that we think showed interactive computing interfaces can now be built anywhere," says Jyri Huopaniemi at Nokia's research lab in Tampere, whose team built the touchscreen, dubbed Ubice, or ubiquitous ice.

Finland has a tradition of building snow and ice sculptures during its long winter. It was these that inspired the device, says Antti Virolainen, a member of the Nokia team. "We decided to see if we could make an ice sculpture that was interactive."

The team commissioned a firm in nearby Oulu to retrieve a tonne of 25-centimetre-thick river ice, and used a chainsaw to cut it into 50-centimetre-square slabs. They used these to make a 2-metre by 1.5-metre ice wall and then blasted the surface with a heat gun - more typically used for stripping paint - to create a smooth surface.

The team made their wall an interactive one by using digital projection technology, rather than peppering the ice with sensors that would raise the cost of the installation, Virolainen told the Interactive Tabletops and Surfaces conference in Saarbr�cken, Germany, last week. The icescreen uses rear-diffused illumination (RDI), a technique first used by Microsoft in its table-based interactive touchscreen, Surface, launched in 2008.

A near-infrared light source mounted behind the "screen" bathes it in invisible light, and an array of near-infrared cameras, also behind the wall, are focused on the front surface. A hand placed on the ice reflects the light towards the camera array and the signal each camera receives helps a nearby PC establish the hand's position, size and motion. The PC is also connected to a projector, which uses the data to project imagery - such as flames - beneath the user's hand.

"It was -15 �C out there so it was very interesting to show ice on fire," says Virolainen. "It wouldn't have been anywhere near as interesting with a plastic screen."

Patrick Baudisch of the University of Potsdam in Germany, who has turned toy building blocks and floors into interactive devices, says the touchscreen could be compared to Microsoft Surface, with flaws in the ice limiting the accuracy with which it can locate a user's hand. "But that would miss the point. This is a wonderful piece of work and a quirky idea."

Nokia suggests ice sculptors, or owners of ice buildings like the Ice Hotel in Jukkasj�rvi, Sweden, could make a feature of the technology.

"Playful experiments like this are important - people really liked it," says Huopaniemi. "New forms of interaction, sensing and content delivery for future mobile devices could come out of it."

New forms of interaction, sensing and content delivery could come out of the technology

What is ubiquitous computing?

Also known as pervasive computing, it describes a new mode of interaction in which computers leave the confines of our desks and laps to become partly embedded in our surroundings, allowing people to interact with many types of computer-generated media without using a formal computer.

Nokia's Ubice is one such notion; another recent exponent of ubiquitous technology was Microsoft, with its LightSpace system (New Scientist, 6 October, p 21). This turns surfaces in a meeting room or lecture hall into a display for projected documents, photos or video. Presenters can even "pick up" a virtual item from one display and move it to another.